PROJECT SUMMARY/ABSTRACT This K99/R00 award will prepare Dr. Genoa Warner for an independent research career, with the main goal of providing Dr. Warner with all the technical and profession skills necessary for her to become a successful independent investigator and leader in the field of reproductive toxicology. Dr. Warner has extensive training in endocrine disruption and sustainable chemistry and is currently a postdoctoral fellow in reproductive toxicology at the University of Illinois under the mentorship of Dr. Jodi A. Flaws. This award will enable Dr. Warner to expand her research training in reproductive biology and allow her to draw from her diverse scientific background in chemistry and biology to investigate important research questions in environmental health. These goals will be accomplished with the support of Dr. Warner's exceptional mentoring team, composed of Dr. Flaws, Dr. Susan Schantz, Dr. Heather Stapleton, and Dr. John Katzenellenbogen. The research proposal and career development plan created by Dr. Warner with the guidance of her mentoring team will provide Dr. Warner with new experimental techniques and skills needed to establish an independent research program. In the research training component of this proposal, Dr. Warner will investigate the mechanisms by which phthalates, a group of endocrine disrupting chemicals with ubiquitous human exposure, cause ovarian follicle toxicity. Further, she will investigate the metabolism of phthalates by ovarian tissue because phthalate metabolites mediate phthalate- inducted toxic effects, contributing to infertility and premature ovarian failure. In the prosed studies, Dr. Warner will use environmentally relevant concentrations of six phthalates as a mixture and individually. Specific Aim 1 (mentored phase) will identify how phthalates partition into ovarian tissue during culture via mass spectrometry and imaging methods using chemically modified phthalates. Specific Aim 2 (mentored and independent phases) will determine how phthalate toxicity varies between cell types of the ovary by culturing populations of each cell type found in the ovarian follicle with phthalates. Finally, Specific Aim 3 (Independent Phase) will identify the genomic localization of phthalates in the ovary by adapting the biochemical technique of chemical affinity capture paired with massively parallel DNA sequencing (Chem-seq) to provide information on the genes and proteins targeted by phthalates. Overall, the proposed studies will provide novel chemical and mechanistic insight into causes of phthalate-induced toxicity in the ovary that contribute to female infertility and premature ovarian failure. The methods combine chemical and biological techniques to develop a new, widely applicable technology for investigating the mechanisms of endocrine disrupting chemicals that will provide the basis for Dr. Warner's independent career.